Molecular precursor-mediated facile synthesis of photo-responsive stibnite Sb 2 S 3 nanorods and tetrahedrite Cu 12 Sb 4 S 13 nanocrystals.

Stibnite Sb 2 S 3 and tetrahedrite Cu 12 Sb 4 S 13 nanostructures being economical, environmentally benign and having a high absorption coefficient are highly promising materials for energy conversion applications. However, producing these materials especially tetrahedrite in the phase pure form is a challenging task. In this report we present a structurally characterized single source molecular precursor [Sb(4,6-Me 2 pymS) 3 ] for the facile synthesis of binary Sb 2 S 3 as well as ternary Cu 12 Sb 4 S 13 in oleylamine (OAm) at a relatively lower temperature. The as-prepared Sb 2 S 3 and Cu 12 Sb 4 S 13 nanostructures were thoroughly checked for their phase purity, elemental composition and morphology by powder X-ray diffraction (pXRD), electron dispersive spectroscopy (EDS) and electron microscopy techniques. pXRD and EDS studies confirm the formation of phase pure, crystalline orthorhombic Sb 2 S 3 and cubic Cu 12 Sb 4 S 13 . The SEM, TEM and HRTEM images depict the formation of well-defined nanorods and nearly spherical nanocrystals for Sb 2 S 3 and Cu 12 Sb 4 S 13 , respectively. The Sb 2 S 3 nanorods and Cu 12 Sb 4 S 13 nanocrystals exhibit an optical bandgap of ∼1.88 and 2.07 eV, respectively, which are slightly blue-shifted relative to their bulk bandgap, indicating the quantum confinement effect. Finally, efficient photoresponsivity and good photo-stability were achieved in the as-prepared Sb 2 S 3 and Cu 12 Sb 4 S 13 nanostructure-based prototype photo-electrochemical cell, which make them promising candidates for alternative low-cost photon absorber materials.